As you know, I changed to a 9" rear end. Also, I was having problems with the rear half of the exhaust pipes rattling against the new rear housing and leaf spring hangers so had that replaced.I have driven the car but up until Tuesday had not gotten above 45mph. Well Tuesday I drove the car to the golf course and got up towards 60-70. When at those speeds, I have a noise I will call it. I can also feel it in a vibration. Worries me. I have the car up on jack stands right now trying to see if something is amiss. Any input? Checking the driveshaft for issues. Not sure what it is, but if I can't locate the issue, Roger would you be willing to go for a little ride and see what you think. I will keep it under 100. Unless someone wants to race. Larry

Bill, it is interesting that you mention the driveline. It was an 8" before and when I put the 9" in the car, the old driveshaft was too long. I was going to get it shortened. Took it in and they showed me it was totally worn out. So, made a new one, 4" diameter instead of 3" much beafier u-joints.I gave them measurements, but it actually looks a little short. Maybe it isn't in the transmission far enough. Not sure, appreciate your help. Thanks Larry

You did a lot of swapping of bits in this car... so have you ever checked driveline angles? If you have a smartphone Tremec makes an app for this analysis. If not, Google this. If the angle of the engine and rear end are out of sync from each other, the u-joints in the driveline with not rotate as designed. Not so much a vibration as it is a resistance to movement causing a seeming imbalance. I have a similar issue on my Ranchero - also with all new rear end and driveline, and I think this is the next thing I'm going to be checking on it.

Roger, this really makes sense that it is my issue. I didn't think the noise or vibration was coming from the rear end. It felt more like it was related to the driveshaft. That is why I thought maybe it was too short. Thanks and I will check it as soon as I figure how to get it raised up and level. Thanks Larry

Of course you should check transmission tail-shaft/slip yoke engagement. You should have about 3/4"-1" visually exposed (see note below) - just enough to be able to push the driveline into the transmission a little further when removing the rear u-joint from the 3rd member.

Note: Some early extension housing tail-shaft seals were two depth seals. The end pressed into the transmission was like a regular seal, but it had a rubber dust shield as part of it to protect this otherwise exposed 3/4"-1" part of the slip yoke. This shield kept that part of the driveshaft from rusting, but still allowed you to push the slip yoke into the transmission. Lacking this dust shield you could basically ruin the seal when you pushed the slip yoke into the tail-shaft when removing the driveline; especially if the slip yoke had significant surface rust on it. Not all replacement seals look like this and you should clean any rust off the exposed area of the slip yoke when pulling the driveline.

Well, as usual Roger has given the advice that I believe is my problem. I went underneath and was going to check pinion angle, but didn't get that far. I found that the traction bars that we made were holding the rear end in a nose down position.I took off the rubber bumpers at the front of the bars, and the pinion angle is better, (will have to measure) but now the traction bars are touching the fasteners that hold the leaf springs together. So, I will have to remove the bars, then check pinion angle. But that creates another problem. The bars are welded to the leaf spring shock absorber plates where the u bolts attach the rear end to those plates. Now, does anyone happen to have a spare set of those plates lying around you want to get rid of.Don't know what years will work. I do know that I had to slot the holes just a little in my plates to get the u bolts installed because the diameter of the 9" housing was just a little bigger. Thanks for all the help and I will keep you all informed on the progress. Larry

More investigation shows that the traction bars were really torqueing the leaf springs and holding the rear end with the pinion facing down. Just the opposite of what it should be. It will be very hard to cut the welds on the plates/traction bars, but that is where I guess I'll start. More to come. Larry

Not getting a lot done on this car. Headaches will not let me lie down under this thing. The traction bars that I had installed were indeed preloading the leaf springs holding the rear end facing down 4-5 degrees. Just the opposite of what it is supposed to be.I cut the traction bars off the leaf spring plates and installed the rear end again. Now the rear end is still pointing down just a little. The way the leaf springs were preloaded has created a warp in the springs that is visibly causing the rear end to point down.When I first started this car rebuild it was evident that the leaf springs were weak and thought about replacing them. But, decided to try the old ones.Now that these are so weak and warped I am going to replace with new.Here is my question. Since I plan on racing the car, and since I like the rear end up just a little bit, should I go with 5 leaf springs? I know the ride is supposed to be stiffer, but it can't be as bad as it was with the traction bars holding it stiff. Thanks Larry

Ordered leaf springs from McVeigh and the Cal Tracs for the car. Going with 4 leaf springs instead of 5. Thought about making the cal tracs, doesn't look that hard, but so many problems with the homemade traction bars before, don't want more problems. Larry

It may take some trial and error to sort out. There is a company in Spokane called watts wheel and driveline that I have used for years. They build custom driveline and even wheels for race cars. I think they have been around as long as I can remember. At least into the mid sixties.

There must be something similar on your side of the mountains, or give Watts wheel a call and see what they say.

Thanks Bill. In changing over to this 9" rear end I have found some underlying issues that I am sure were there before the swap. No. 1 is the biggest culprit. My neighbor made some traction bars for me and they were beautiful. But, I just bolted them on never checked what they were doing to the pinion angle. Just never crossed my mind that they would change anything.The rubber pads at the front of the traction bars were contacting the front of the leaf springs. They were hitting so hard, that they were bending the leaf springs and forcing the rear end so that the pinion was pointing down.Here is another issue that I have found out now that I have those bars off. My car was sitting with the back of the car up a little more than the front, which I liked. But I thought the car was being held up at the back by my air shocks. Well, now that the bars are off, the rear of the car is quite a bit lower now. Also now that the bars are off, there is a bend in the leaf springs that was caused by the warping affect of the bars. Also, there is zero curve to the leaf springs when on the ground. As a matter of fact there may be a little negative bend to them. I tried putting some spacers between the axle housing and the leaf spring plates to make the pinion angle better, but all that happened is the leaf springs just bend. Just the weight of the rear end makes it tweak out of position. Sooooo I ordered the new leaf springs. Then I will set the pinion angle, which really isn't that difficult to do. Did it before when I installed the new engine and the old rear end a few years ago. Got a lot of good info on that from Pat.After I have the pinion angle set, then I will install the Cal Trac traction system that I just ordered. More to come I am sure. Larry